Well in these situations when response is minimal, you should open a support case. This forum does not provide official support, it's just the user community as well as Symantec employees who do it on their free time.
From what I can gather, you may have some malicious activity occurring on a PC? Is it exhibiting any other signs other than that protocol showing up?
Can you post a screenshot of what you're seeing?
In the LAN properties what is showing? Here is a screenshot of mine: